Safety needle apparatus and method

ABSTRACT

Disclosed is a safety catheter that automatically sheaths the needle upon withdrawal of the needle from a patient. The catheter can include a plunger for drawing a vacuum to draw blood or alternatively may delete the plunger and use nearly identical components with the addition of a blocking plug. The catheter also includes a cap/re-cap device that provides additional sheathing of the needle during assembly, shipping, and use of the needle. It also includes raised indicia that serves as a trademark as well as a friction gripping surface. The catheter includes improved catheter hub mounting structure as well as strengthened ribbed areas for grasping during use of the catheter.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation of application Ser. No. 09/477,213, filedJan. 4, 2000, now U.S. Pat. No. 6,156,015, which is a continuation ofapplication Ser. No. 09/102,467, filed Jun. 22, 1998, now U.S. Pat. No.6,010,487, which is a continuation of application Ser. No. 08/823,830,filed Mar. 25, 1997, now U.S. Pat. No. 5,769,827, which is acontinuation of application Ser. No. 08/296,329, filed Aug. 25, 1994 nowabandoned. Each application identified above is incorporated here byreference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] NOT APPLICABLE

BACKGROUND OF THE INVENTION

[0003] This invention relates to safety needles of the type used topuncture the skin of patients. More particularly, this invention relatesto intravenous catheters that protect the needle both before use andupon withdrawal from a patient.

[0004] Safety needles and catheters are old in the art. For example,safety catheters are disclosed in: (1) U.S. Pat. No. 4,834,718 (“the'718 patent”) issued on May 30, 1989, to Michael McDonald; and (2) U.S.Pat. No. 4,944,725 (“the '725 patent”), issued on Jul. 31, 1990, toMichael McDonald. Mr. McDonald is one of the inventors of the presentinvention in this application.

[0005] The catheter in the '718 patent was the first catheter to provideconvenient, reliable, economical, and automatic sheathing of the needleupon withdrawal of the needle from the patient. The '725 patentdiscloses improvements to Mr. McDonald's first patented structure in the'718 patent. The applicants hereby incorporate by reference the completedisclosures of the '718 and '725 patents.

[0006] The structures shown in the '718 and '725 patents weresignificant advances in the art. They included “flash back” chambers todetermine, by relatively small sliding movement of an outer housing awayfrom the catheter, whether the vein had been punctured sufficiently sothat blood would flow through the catheter and needle into the flashback chamber where the blood could be seen at the back of the housing.

[0007] These prior structures, however, were not as effective in drawingblood into the flash back chamber when used on trauma patients with verylow blood pressure. For these types of patients, the blood pressure ofthe patient can be too low to force blood through the catheter andneedle into the flash back chamber in the housing. These prior artdevices did not provide any way to draw a substantial vacuum in thehousing in order to draw blood from the trauma patient into the flashback chamber when the needle and associated catheter penetrate the veinof the patient.

[0008] Other safety needles in the art have employed plungerspenetrating the back of the needle housing to draw a vacuum in thehousing. None of these prior art structures, however, have provided sucha vacuum plunger for the McDonald safety needles shown in the '718 and'725 patents.

[0009] Another problem with the prior art safety catheters and needlesis the lack of capping structure for complete capping of the entireneedle and catheter during assembly, shipping, and pre-use handling.Thus, the prior art catheters and needles such as shown in the '718 and'725 patents provided an exposed needle during needle assembly andshipping. The needles are also exposed when removed from their packagingand prior to actual alignment for injection into the patient. Thisbrings about risk of inadvertent needle sticks to manufacturers andneedle operators, and subsequent inappropriate use of the same needleson patients. Accidental needle sticks can have dire consequences andhave long been recognized as a great problem in the industry and,indeed, in society in general.

[0010] Needles such those shown in the '718 patent and '725 patent dosheath the needle upon withdrawal from the patient. This provides thegreat advantage of automatic sheathing and protection against needlesticks upon withdrawal, but it leaves the operator without the comfortof having taken any action on his or her own to cover the needle.Existing paramedics, nurses, and doctors in the field are oftenaccustomed to the prior art devices that do not automatically sheath theneedle upon withdrawal from the patient. These types of operators areoften most comfortable with capping of the needle whether it isnecessary or not. The prior safety catheters of the '718 and '725patents, and other safety catheters in the prior art, did not provideany such additional capping feature, probably because it appears to beunnecessary. It is often necessary, in fact, however, since such a capcan put certain types of operators at ease and reduce their reluctanceto use a safety needle such as that shown in the '718 and '725 patents.

[0011] The prior McDonald safety catheters of the '718 and '725 patentsincorporated needle hub design that had a reduced and thin neck (shownas number 36 in FIG. 1 of the '718 patent). This neck is easy for theoperator to grasp and hold in place with one hand while simultaneously,with the other hand, pulling back on the outer housing and thusautomatically sheathing the needle within the needle housing. Thereduced diameter neck is relatively weak, however, and may be subject tobreakage when in use out in the field.

[0012] Finally, the prior McDonald safety catheter employed acylindrical outer housing with a smooth, transparent plastic surface.The operator grasps and pushes and pulls on the this smooth surface whenusing the device out in the field. Although this cylindrical transparentdesign is particularly effective and reliable for a number of reasons,the operator's fingers can slip on the smooth surface, particularly whenwet, and risk puncturing the patient incorrectly or at least not asaccurately as desired. An incorrectly positioned needle puncture, whichmisses the vein or goes through it, can be painful and cause bleeding.

OBJECTS OF THE INVENTION

[0013] It is therefore an object of the present invention to develop asafety catheter and needle that develops a vacuum to draw blood into theflash back chamber when the needle is used on trauma patients having lowblood pressure.

[0014] It is yet another object of the present invention to develop sucha safety catheter and needle that provides protection against accidentalneedle sticks during needle and catheter assembly and shipping.

[0015] A further object is to provide a needle that also protectsagainst accidental sticks upon opening of the needle package, removal ofthe needle from the package, and pre-use manipulation of the needle andcatheter.

[0016] Another object is to provide a catheter and needle that alsoprovides recapping structure to allow the operator to place an otherwiseseparate cap over the needle after its withdrawal from the patient.

[0017] Yet another object is to provide a single cap structure thatprovides both pre-use capping and post-withdrawal capping of the needle.

[0018] A still further object of the invention is to provide a catheterand needle housing that is less subject to slipping in the hands of auser while still being predominantly transparent and generallycylindrical for easy use and grasping.

[0019] Another object is to provide a safety catheter that is stronger,and less subject to accidental breakage in use, than prior catheters andneedles.

[0020] An additional object is to provide a safety catheter that meetsthe prior objects while providing a safety catheter that is convenient,easy and economical to manufacture, assemble, and ship, slim yet sturdy,and easy to use and dispose of properly and safely.

[0021] There are other objects that will become apparent as thespecification proceeds.

SUMMARY OF THE INVENTION

[0022] The foregoing objects and advantages are attained by ourinvention of an improved safety needle, preferably a catheter needle,that has an outer housing and an inner needle housing slidably mountedin the outer housing. The inner needle housing includes a cathetermounting end opposite the junction of the needle housing and the outerhousing. Preferably, a removable cap, which is preferablyfrusto-conical, has one end mountable about the catheter mounting endand another end mountable on the outer housing. The cap can be mountedon the inner needle housing to protect against needle sticks duringshipping of the inner needle housing and assembly of the catheter on theneedle and the inner housing within the outer housing. The cap can thenbe reversed and mounted on the outer housing to protect against needlesticks during packaging, shipment, and pre-insertion manipulation of thecatheter. Preferably, after withdrawal of the needle, the cap can beremounted on the outer housing to provide protection against accidentalsticks after use of the needle and during disposal.

[0023] The outer housing may include a plunger penetrating the outerhousing on the side of the outer housing opposite the needle. Theplunger is slidably mounted in the outer housing to draw a vacuum withinthe outer housing. Alternatively, the plunger may be omitted and theplunger passage blocked with a plug.

[0024] The outer housing may also include a gripping friction surfacewhich preferably results from embossing a trademark or suitable indiciaon the outer surface of the outer housing. The inner needle housing mayalso include ribs or columns on the periphery of the needle housing tostrengthen it while minimizing material use and providing graspingsurfaces on the needle housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The preferred embodiments of the applicants' invention aredepicted in the following drawings in which:

[0026]FIG. 1 is an exploded isometric view of the major components ofthe preferred catheter embodiment having a plunger, a separable needlecap, and an embossed trademark/friction surface on the outer housing;

[0027]FIG. 2 is a partial plan view of the catheter needle of FIG. 1after assembly and showing the plunger in partial cutaway within thehousing;

[0028]FIG. 3 is a partial cross-sectional view through section line 3-3of FIG. 2, showing the indicia embossing of the outer wall of the outerhousing;

[0029]FIG. 4 is a cross-sectional view of the preferred plunger cathetershowing the narrow end of the cap mounted on the inner needle housing tocover the needle during shipment and assembly;

[0030]FIG. 5 is a cross-sectional view of the preferred plunger cathetershowing the cap being removed from the inner needle housing afterassembly of the inner needle housing within the outer housing of thecatheter;

[0031]FIG. 6 is a cross-sectional view of the preferred plunger cathetershowing the cap inverted from the orientation of FIG. 5 and mounted onthe outer housing to cover the catheter and needle during packaging,shipment, removal from the packaging by the user, and pre-usemanipulation of the catheter;

[0032]FIG. 7 is a cross-sectional view of the preferred plunger cathetershowing removal of the cap from the outer housing prior to insertion ofthe needle and catheter into the patient;

[0033]FIG. 8 is a cross-sectional view of the preferred plunger cathetershowing the withdrawal of the needle from the patient and automaticsheathing of the needle within the inner needle housing;

[0034]FIG. 9 is a cross-sectional view of the preferred plunger cathetershowing the cap mounted once again on the outer housing to furtherprotect the inner housing and needle within the inner housing; and

[0035]FIG. 10 is a cross-section view of the preferred catheter withoutthe plunger and with a flash back plug abutting and thus blocking theplunger passage in the back of the outer housing.

[0036] This description of the preferred embodiment utilizes spacialorienting terms such as “back” and “outer.” It is to be understood thatthese terms are used for convenience of description and not themselveslimiting or requiring a particular location in space.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Referring now to FIG. 1, the applicant's preferred plunger safetyneedle, generally 10, has a plunger rod 12 and plunger 14, a needlemounting cylinder 16, a needle 18, a catheter 20, an inner needlehousing 22, an outer handle housing 24, and a cap 26. The plunger rod 12consists of an “X” shaped plunger beam 28 extending perpendicularly froma planar plunger end cap 30. The plunger beam 28 slidably penetrates theopen end 31 of a cylindrical flash back chamber 32 on the interior ofthe needle mounting cylinder 16; and the needle 18 is mounted on the endof the needle mounting cylinder 16 opposite the open end 31 of the flashback chamber 32.

[0038] The needle mounting cylinder 16 slidably penetrates an openpassage 34 in the needle housing 22. In turn, the needle housing 22, theneedle mounting cylinder 16, plunger rod 12, and plunger 14 are mountedwithin the generally cylindrical interior wall 36 of the outer handlehousing 24. The plunger beam 28 of the plunger rod 12 slidablypenetrates and abuts the “X” shaped plunger passage 38 cooperativelyprovided by the mating upper 40 and lower 42 halves of the handlehousing 24 when sonically welded together with the needle housing 22 andthe associated structure assembled within the handle housing 24.

[0039] The plunger rod 12 is thus slidably mounted in the plungerpassage 38 to slidably penetrate the cylindrical flash back chamber 32within the needle mounting cylinder 16. In turn, the substantiallycylindrical needle housing 22 slidably penetrates a housing passage 44provided within the interior wall 36 of the handle housing 24.

[0040] The catheter 20 has a skin penetration tube 46 coaxiallyextending from an expanded catheter hub 48. The catheter hub 48 mountson the catheter mount 50 extending from the needle housing 22, and thecap 26 is mountable on the needle housing 22 or the handle housing 24 asexplained below.

[0041] Referring now to FIG. 2, the plunger beam 28 has a resilientplunger 14 mounted within and slidably abutting the interior wall 52 ofthe needle mounting cylinder 16. Thus, when the plunger cap 30 is drawnaway from the handle housing 24 and air cannot enter through the needle18 (not shown in FIG. 2) into the interior vacuum space 54 within theneedle mounting cylinder 16, the plunger 14 slides within the mountingcylinder 16 in the same direction and simultaneously draws a vacuum inthe interior vacuum space 54. If the needle 18 has penetrated the veinof a patient (not shown) when the vacuum is drawn in the interior vacuumspace 54, blood is urged to flow from the vein, through the needle, andinto the vacuum space 54.

[0042] The outer surface of the handle housing 24 includes trademarkindicia 56. With reference to FIG. 3, the indicia 56 projects from theouter surface of the housing 24. The raised indicia 56 not only canidentify the product and convey information about the product 10 butalso can provide a surface that is more likely to cause greater frictionin the hands of a user and less likely to result in slippage when inuse. This is particularly helpful in an emergency, when sweaty palms andother fluids, including blood, etc., may otherwise render the outersurface of the handle housing 24 quite slippery. The preferred indicia56 are cut into the molds for the needle housing 24 so that the indicia24 are included into the transparent housing 24 automatically whenmolded. Other surface alteration or scoring may also be utilized.

[0043] Referring now to FIG. 4, the cap 26 is frusto-conical and thushas a larger somewhat cylindrical end 58 opposite a narrower somewhatcylindrical end 60. The cap is made out of resilient material, and itsnarrower end 60 is mountable on the narrowed cap mounting hub 62 on theneedle housing 22. The cap mounting hub 62 is intermediate the widerneedle mounting housing central body 64 and the narrower raised columnguard hub 66. When mounted on the hub 62, the cap 26 thus provides aprotective shield around the needle 18 extending from the needle housing22 when the needle mounting cylinder 16 is placed within the needlehousing 22 as shown in FIG. 1. In this manner, the partial needleassembly 99 (consisting of the needle housing 22, needle mountingcylinder 16, needle 18, and cap 26) can be shipped or moved from oneassembling or manufacturing area to another with significantly reducedrisk of any accidental needle stick to an assemblers, handlers, etc.

[0044] With reference now to FIG. 5, the cap 26 is readily removed by anoperator. The partial needle assembly 99 can then be further assembledinto the handle housing 24 as shown in FIG. 1.

[0045] With the cap 26 removed, the next manufacturer can install thecatheter 20 by sliding it over the needle 18 so that the catheter hub 48mounts on the catheter mount 50. The catheter mount 50 has a cylindricalmounting body 71 with diametrically opposed catheter hub engaging arms72, 74 extending radially outwardly from the mounting body 71. Thecatheter hub 48 has a radially extending detent or undercut 76penetrating the cylindrical interior wall 78 of the catheter hub 48.

[0046] Referring now to FIG. 6, the catheter hub 48 mounts on thecatheter mount 50 and is retained in place on the mount 50 by theradially extending arms 72, 74, which penetrate the radially extendingundercut 76 in the catheter hub 48. The catheter hub 48 is made ofresilient material and is held in place by the arms 72, 74 until theoperator forces the catheter 20 off of the mount 50 until it is fullyseparated from the needle housing 22.

[0047] Still referring to FIG. 6, the larger end 58 of the cap 26 has aninternal radial rib or lip 68. The handle housing 24 has a mating radialdetent 70 on the needle end 61 of the handle housing 24 opposite theplunger end cap 30 (not shown in FIG. 6). The larger end 58 of the cap26 is mounted on the needle end 61 so that the cap's internal rib 68abuts the radial detent 70 in the housing 24. In this manner, theprotective cap 26 is mounted on the handle housing 24 to extend from thehousing 24 and surround the needle 18 and catheter 20. The protectivecap 26 once again provides a protective sheath around the needle 18 andcatheter 20 to minimize accidental needle sticks during (i) furtherpackaging, shipment, and handling of the packaging, (ii) opening of thepackaging, and (iii) pre-use manipulation of the catheter 10 prior toactual use to puncture the skin of a patient.

[0048] Referring now to FIG. 7, when the operator is ready to use theneedle 18 and catheter 20, the cap 26 may be pulled off of the handlehousing 24 (not shown). The operator may now insert the needle 18 andcatheter 20 into the patient as described in the '718 and '725 patents.

[0049] Referring back to FIG. 5, the raised column guard hub 66, whichis exposed upon removal of the cap 26, provides significant strengthwith minimum material between the cap mounting hub 62 and cathetermounting hub 50 on the needle housing 22. The operator can readily graspthis area 66 of the needle housing to hold the housing 22 whenwithdrawing the needle 18 from the patient (not shown). In thisoperation, the handle housing (not shown in FIG. 5) can be drawn awayfrom the patient with one hand while grasping the guard hub 66 andholding it in place as (i) the needle 18 is drawn out of the patient,(ii) the mounting hub 50 separates from the catheter hub 48 as shown inFIG. 7, (iii) the needle 18 slides out of the catheter 20 as also shownin FIG. 7, and (iv) the needle 18 is drawn into the needle housing 22 asshown in FIG. 8. This operation is described in greater detail in the'718 and '725 patents.

[0050] Now that the operator has completed use of the needle 18, theoperator can, as shown in FIG. 9, slide the large end 58 of the cap 26over the needle housing 22 to yet again engage the radial detent 70 andsecure the cap 26 on the handle housing 24. The same cap 26 thusprovides yet another level of protection against subsequent needlesticks. This cap-remounting procedure also provides the clinician,particularly one who is accustomed to manual capping of needles afteruse, with a greater level of comfort and security in using the safetyneedle 10. It also reduces the likelihood that the cap 26 will be leftbehind on the street or any other accident or trauma location.

[0051] Referring now to FIG. 10, the cap 26, indicia 56, (FIG. 1) on thehousing 24, mounting hub 50, and catheter hub 48 described above mayalso be used on a safety needle not having a plunger at all. This typeof catheter is preferably for use with patients having sufficient bloodpressure. This non-plunger needle 100 has a resilient plug 102 mountedwithin the mounting cylinder 16 to extend therefrom and abut thegenerally planar interior end 104 of the needle housing 24. The plug 102thus abuts the “X” shaped plunger passage 38 and prevents the flow ofblood from the flash back chamber 32 through the plunger passage 38.

[0052] The protective cap 26, plunger rod 12 and catheter hub 48 arepreferably made from polypropylene. The plug 102 is made from rubber,and the handle housing 24 and needle mount 16 are made from high impactpolystyrene. The needle is made of steel. The catheter 20 is made fromradiopaque Teflon, and the needle housing 22 is made from ploycarbonate.

[0053] It can thus be seen that the applicants have invented a safetycatheter and needle that is safer than prior art catheters and needlesand yet convenient, economical, and easy to assemble and manufacture. Itprovides numerous significant advantages over the prior art, and it doesso at minimal cost.

[0054] While in the foregoing the applicants have described theirpreferred embodiments, it is to be understood that the scope of theinvention is to be determined by reference to the following claims.

1. An improved needle apparatus comprising in combination: a. a firsthousing having a first end; b. a needle secured to said first housing,extending beyond said first end, and having a point which can beinjected into a patient; c. a second housing movably captured withrespect to said first housing, said second housing having a first endand an opposite end, wherein said first housing and needle are manuallymovable, with respect to said second housing, between a needle exposingposition at which said needle point is outside said second housing, anda needle sheathing position at which said point is withdrawn into saidsecond housing after said needle is fully withdrawn from a patient toprevent an accidental needle stick; and d. a one-piece removable caphaving a first end adapted for engaging said first housing to provide asheath for said needle, and also having a second end adapted forengaging said second housing to provide a sheath for said needle.
 2. Theneedle apparatus of claim 1 , wherein said needle has an axiallyextending internal passage, and said second housing includes a generallycylindrical internal wall defining a chamber communicating with saidinternal passage.
 3. The needle apparatus of claim 2 , furthercomprising a plunger disposed within said generally cylindrical internalwall and slidably engaging said generally cylindrical internal wall todefine a piston.
 4. The needle apparatus of claim 3 , further comprisinga plunger rod having a first portion secured to said plunger and asecond portion accessible to a user for sliding said plunger within saidgenerally cylindrical internal wall.
 5. The needle apparatus of claim 1, further comprising a catheter, wherein said needle is inserted throughsaid catheter when in said needle exposing position and removed fromsaid catheter when in said needle sheathing position.
 6. The needleapparatus of claim 1 , wherein the opposite end of said second housingis disposed within at least a portion of said first housing.
 7. Theneedle apparatus of claim 1 , wherein at least one of said first andsecond housings has an exterior portion accessible for grasping andprovided with a grip.
 8. The needle apparatus of claim 1 , wherein saidgrip is formed by raised indicia on said exterior portion.